Patents by Inventor Rakesh Roshan
Rakesh Roshan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9326348Abstract: An illumination system comprises at least two light sources (101,102,103) having different emission spectra to one another; a detection circuit (131,132,133) for sensing a light intensity using at least one of the light sources as a photosensor; and driving means (161,162,163) for driving the light source in dependence on the sensed spectral distribution of light. The emission spectrum of a light source with the smallest bandgap overlaps the emission spectrum of a light source with the second-smallest bandgap. The illumination system is possible to measure the intensity of light emitted by the light source with the smallest bandgap by putting the light source with the second-smallest bandgap in detection mode. The illumination system may also sense the spectral distribution of ambient light, to allow the output from the illumination system to be adjusted in dependence on the ambient light.Type: GrantFiled: March 23, 2008Date of Patent: April 26, 2016Assignee: Sharp Kabushiki KaishaInventors: Rakesh Roshan, Benjamin James Hadwen, David James Montgomery, Jonathan Heffernan
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Patent number: 7979766Abstract: An aspect of the present invention reduces the additional number of signal lines of a bus for control signals by using a set of signal lines to transfer data bits in some durations and to transfer control signals in some other durations. In one embodiment, the same signal lines are used to transfer data in a data transfer phase, and for bus arbitration in a bus arbitration phase. As a result, the total number of signal lines of a bus (bus width) is reduced. According to another aspect of the present invention, an arbitrator block allocates the bus to one of the requesting modules according to an assigned priority and least recently used (LRU) policy.Type: GrantFiled: September 8, 2004Date of Patent: July 12, 2011Assignee: Centre for Development of TelematicsInventors: Manish Sharma, Rakesh Roshan, Manjunath Bittanakurike Narasappa, Bhavani Shanker Arunachalam, Suresh Radhakrishna, William Clement, Joe Jaisingh
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Publication number: 20100182294Abstract: An illumination system comprises at least two light sources (101,102,103) having different emission spectra to one another; a detection circuit (131,132,133) for sensing a light intensity using at least one of the light sources as a photosensor; and driving means (161,162,163) for driving the light source in dependence on the sensed spectral distribution of light. The emission spectrum of a light source with the smallest bandgap overlaps the emission spectrum of a light source with the second-smallest bandgap. The illumination system is possible to measure the intensity of light emitted by the light source with the smallest bandgap by putting the light source with the second-smallest bandgap in detection mode. The illumination system may also sense the spectral distribution of ambient light, to allow the output from the illumination system to be adjusted in dependence on the ambient light.Type: ApplicationFiled: March 23, 2008Publication date: July 22, 2010Inventors: Rakesh Roshan, Benjamin James Hadwen, David James Montgomery, Jonathan Heffernan
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Publication number: 20100115357Abstract: An aspect of the present invention reduces the additional number of signal lines of a bus (180) for control signals by using a set of signal lines to transfer data bits in some durations and to transfer control signals in some other durations. In one embodiment, the same signal lines are used to transfer data in a data transfer phase, and for bus arbitration (150) in a bus (180) arbitration phase. As a result, the total number of signal lines of a bus (180) (bus width) is reduced. According to another aspect of the present invention, an arbitrator (150) block allocates the bus (180) to one of the requesting modules according to an assigned priority and least recently used (LRU) policy.Type: ApplicationFiled: September 8, 2004Publication date: May 6, 2010Applicant: Centre for Development of TelmaticsInventors: Manish Sharma, Rakesh Roshan, Manjunath Bittanakurike Narasappa, Bhavani Shanker Arunachlam, Suresh Radhakrishna, William Clement, Joe Jaisinch
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Patent number: 7686493Abstract: A display comprises a light source and an image display panel disposed in an optical path from the light source. The light source comprises a primary light source for illuminating a re-emission material which comprises at least a first nanophosphor material for, when illuminated by light from the primary light source, re-emitting light in a first wavelength range different from the emission wavelength range of the primary light source. The image display panel comprises a first filter having a first narrow passband or a first narrow absorption band, the first narrow passband or first narrow absorption band being aligned or substantially aligned with the first wavelength range. The combination of a narrow wavelength range emitted by the first nanophosphor material and the narrow passband or narrow absorption band of the filter allows a display with high efficiency and a high NTSC ratio to be obtained.Type: GrantFiled: October 1, 2007Date of Patent: March 30, 2010Assignee: Sharp Kabushiki KaishaInventors: Rakesh Roshan, Peter Neil Taylor, David James Montgomery
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Patent number: 7605011Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region. The fabrication method of the invention enables the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) to produced after the device structure has been fabricated. This allows the degree of overlap between the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) and the optical mode of the laser to be altered after the device has been grown.Type: GrantFiled: July 24, 2007Date of Patent: October 20, 2009Assignee: Sharp Kabushiki KaishaInventors: Rakesh Roshan, Brendan Poole, Stewart Edward Hooper, Jonathan Heffernan
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Publication number: 20080084706Abstract: A display comprises a light source and an image display panel disposed in an optical path from the light source. The light source comprises a primary light source for illuminating a re-emission material which comprises at least a first nanophosphor material for, when illuminated by light from the primary light source, re-emitting light in a first wavelength range different from the emission wavelength range of the primary light source. The image display panel comprises a first filter having a first narrow passband or a first narrow absorption band, the first narrow passband or first narrow absorption band being aligned or substantially aligned with the first wavelength range. The combination of a narrow wavelength range emitted by the first nanophosphor material and the narrow passband or narrow absorption band of the filter allows a display with high efficiency and a high NTSC ratio to be obtained.Type: ApplicationFiled: October 1, 2007Publication date: April 10, 2008Inventors: Rakesh ROSHAN, Peter Neil TAYLOR, David James MONTGOMERY
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Publication number: 20070263691Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region. The fabrication method of the invention enables the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) to produced after the device structure has been fabricated. This allows the degree of overlap between the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) and the optical mode of the laser to be altered after the device has been grown.Type: ApplicationFiled: July 24, 2007Publication date: November 15, 2007Inventors: Rakesh Roshan, Brendan Poole, Stewart Hooper, Jonathan Heffernan
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Patent number: 7263115Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region. The fabrication method of the invention enables the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) to produced after the device structure has been fabricated. This allows the degree of overlap between the non-absorbing portion(s) (11b) of the saturable absorbing layer (6) and the optical mode of the laser to be altered after the device has been grown.Type: GrantFiled: April 1, 2004Date of Patent: August 28, 2007Assignee: Sharp Kabushiki KaishaInventors: Rakesh Roshan, Brendan Poole, Stewart Edward Hooper, Jonathan Heffernan
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Publication number: 20040233952Abstract: A semiconductor device comprises an active region (4), a cladding layer (5,7), and a saturable absorbing layer (6) disposed within the cladding layer. The saturable absorbing layer comprises at least one portion (11a) that is absorbing for light emitted by the active region and comprises at least portion (11b) that is not absorbing for light emitted by the active region.Type: ApplicationFiled: April 1, 2004Publication date: November 25, 2004Inventors: Rakesh Roshan, Brendan Poole, Stewart Edward Hooper, Jonathan Heffernan
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Patent number: D872170Type: GrantFiled: May 9, 2018Date of Patent: January 7, 2020Assignee: OXSIGHT LIMITEDInventors: Robert Evans, Steve Green, Rupert Wilkinson, Terry Gander, Stephen Hicks, Athar Ali, Rakesh Roshan, Daniel Crown